                (some-> (js-src->cljs-src f) ana/parse-ns :ns))]
       (when ns
         (as-> @env/*compiler* compiler-env
-         (let [t (util/last-modified smf)]
-           (if (or (and (= ns 'cljs.core)
-                        (nil? (get-in compiler-env [::source-maps ns])))
-                 (and (not= ns 'cljs.core)
-                      (> t (get-in compiler-env [::source-maps ns :last-modified] 0))))
-             (swap! env/*compiler* assoc-in [::source-maps ns]
-               {:last-modified t
-                :source-map (sm/decode (json/read-str (slurp smf) :key-fn keyword))})
-             compiler-env))
-         (get-in compiler-env [::source-maps ns :source-map]))))))
+          (let [t (util/last-modified smf)]
+            (if (or (and (= ns 'cljs.core)
+                         (nil? (get-in compiler-env [::source-maps ns])))
+                    (and (not= ns 'cljs.core)
+                         (> t (get-in compiler-env [::source-maps ns :last-modified] 0))))
+              (swap! env/*compiler* assoc-in [::source-maps ns]
+                {:last-modified t
+                 :source-map (sm/decode (json/read-str (slurp smf) :key-fn keyword))})
+              compiler-env))
+          (get-in compiler-env [::source-maps ns :source-map]))))))
 
 (defn ns-info
   "Given a path to a js source file return the ns info for the corresponding

           "(" file (when line (str ":" line)) (when column (str ":" column)) ")"))))))

(comment
  (cljsc/build "samples/hello/src"
    {:optimizations :none
     :output-dir "samples/hello/out"
     :output-to "samples/hello/out/hello.js"
     :source-map true})

  (mapped-stacktrace
    [{:file "hello/core.js"
      :function "first"
      :line 2
      :column 1}]
    {:output-dir "samples/hello/out"})

  (print-mapped-stacktrace
    [{:file "hello/core.js"
      :function "first"
      :line 2
      :column 1}]
    {:output-dir "samples/hello/out"})

  ;; URL example


    {:optimizations :none
     :output-dir "out"
     :output-to "out/hello.js"
     :source-map true}
    st)

  (env/with-compiler-env st
    (mapped-stacktrace
      [{:file "cljs/core.js"
        :function "first"
        :line 2
        :column 1}]
      {:output-dir "out"}))

  (env/with-compiler-env st
    (print-mapped-stacktrace
      [{:file "cljs/core.js"
        :function "first"
        :line 2
        :column 1}]
      {:output-dir "out"}))
  )

(defn- display-error
